Many word processing programs have a function, called spellchecking, for verifying the correctness of the spelling of words in an electronic document. Common spellcheckers verify spelling by comparing words in the document with words in an online dictionary. Any word in the document that is missing from the dictionary the spellchecker fails to recognize and thus flags as misspelled. Sometimes the unrecognized word, however, is in fact correctly spelled, but its absence from the dictionary causes a misidentification. Product names, proper names of people and places, and technical terms are the usual types of words most frequently misidentified.
Upon encountering an unrecognized word, the spellchecker presents a user with three choices: 1) ignore the word; 2) correct the word; or 3) add the word to the dictionary. If the user adds the word to the dictionary, the spellchecker recognizes the word upon each subsequent encounter in the same or in a different document and considers it correctly spelled. Although this satisfies the spellchecker for one particular form of the word, other forms of the same word, however, still cause the spellchecker to present the user with the above-described three choices.
For example, consider the following text in quotations: “An elastomer is a polymer material that recovers its original shape upon release of a deforming stress. This elasticity distinguishes elastomers from plastics. An elastomer's properties make such material suitable for many different products. For example, golf ball covers are commonly made of elastomeric material.” When a spellchecker analyzes this text, the word “elastomer” is flagged as misspelled (i.e., unrecognized). Despite the addition of elastomer to the dictionary, however, the spellchecker still flags the related-word forms “elastomers” (plural), “elastomer's” (possessive), and “elastomeric” (adjective) as misspelled because each of these words remains unrecognizable. This occurs because only the particular form added to the dictionary is considered valid. Each new related-word form is consequently flagged as misspelled and thus needs to be individually added to the dictionary. Consequently, running a spellchecker on a technical document, which often uses many variations of technical terms and proper nouns, can be particularly bothersome if the user needs to pause and add each variation of a related-word form as each related-word form is encountered.